You must acknowledge your sources each time you refer to them in your work.
If you refer to the same source more than once you must acknowledge it each time, otherwise you may be committing a type of plagiarism known as concealing sources.
This is often an unintentional act of plagiarism and displays a lack of understanding of academic conventions or academic writing skills.
The video below further explains this type of plagiarism:
Activity on concealing sources
Now test your understanding of concealing sources by completing the questions below. When you have finished, click ‘Submit’ and review your feedback.